Fluidic switch

ABSTRACT

A four-way switch of particular utility in fluidic computation and control apparatus is disclosed herein. The switch comprises a pivotable switching and control member having a flat surface resiliently biased toward a plane surface of the housing. The plane surface of the housing is perforated in three locations with the perforations being communicated to three mutually independent fluid outlets. The pivotal member includes, on the surface opposed to the flat surface, a detent receiving means for holding the member in either of two pivotal positions and on the flat surface, a channel adapted to intercommunicate the center perforation with either of the other perforations. The pivotal member is further perforated by two passages arranged to communicate the third of the housing member perforations through the valve to the ambient to vent the unused passage system.

United States Patent Inventor Stanley Leszczynski Schenevus, N.Y. 2iAppl. N0. 826,519 22 Filed May 21, 1969 I45] Patented Aug. 17,1971 |73|Assignee The Bendix Corporation [54] FLUIDICSWITCH 3 Clalms,4 DrawingFigs. 52 U.S.Cl tar 625.21

[51] lnt.Cl ..Fl6k 11/02 [50] FieldofSearch ..137/625.21, 596;251/297,180,295

[5 6] References Cited UNITED STATES PATENTS 7 856,652 6/1907 Murphyl37/625.2l 1,938,505 12/1933 Trice et aL... 251/297X 1,969,462 8/1934Hodgkins l37/625.21 X 2,351,732 6/1944 Almond et al.. 137/624.212,377,473 6/1945 Wolcott 251/297X 3,082,791 3/1963 Miller 251/180XFOREIGN PATENTS 1,027,633 4/1966 Great Britain Primary ExaminerM. CaryNelson Assistant Examiner-R. B. Rothman Attorneys- Robert A. Benzigerand Flame, Arens, l-lartz, l-lix and Smith ABSTRACT: A four-way switchof particular utility in fluidic computation and control apparatus isdisclosed herein. The switch comprises a pivotable switching and controlmember having a flat surface resiliently biased toward a plane surfaceof the housing. The plane surface of the housing is perforatedperforated by two passages arranged to communicate the third of thehousing member perforations through the valve to the ambient to vent theunused passage system.

PATENTEDAUGI'IIQYI v 3599.671

FIGURE 4- h FIGURE 3 FIGURE I STANLEY LESZCZYNSK/ INVENTOR.

FLUIDIC SWITCH BACKGROUND OF THE INVENTION 1. Field of the Invention v,The present invention relates to switches adapted to switch fluid flowin systems, particularly in systems utilizing fluidic logic components.

2. Description of the Prior Art The prior art shows a wide variety ofmeans to switch fluid flows between a plurality of passages. However,these means are not wholly consistent with the primary objectives andadvantages of fluid logic control systems (fluidics) since the prior artdevices do not combine all of the necessary attributes of a fluidicswitch.

In switching fluid flows in systems employing fluidic logic components,several important considerations must be-borne in mind. There must be aminimum leakage consistent with maintainingoperating pressuresthroughout the system, but small amounts of leakage at the switch areacceptable since fluidic logic systems utilize venting (controlledleakage) to isolate elements. Furthermore, the expense of such a devicemust be consistent with fluidic systems which are, in general, lowexpense. systems. It is, therefore, an object of the present inventionto provide a low cost switch construction adapted for fluid handlingsystems.

As well as being low in cost, a fluid switch must also have a longuseful service life. It is, therefore, an object of the presentinvention to provide a fluid switch having a long service. It is afurther object of the present invention to provide such a switch whichis substantially rigid in constructionhaving a minimum of moving parts.It is a further object of the present inventionv to provide such aswitch in which wear due to long term usage does not effect partalignment.

Switches used in. fluid handling systems, such as fluidic logic controlcircuitry, are frequently required to communicate a source ofpressurized fluid to at least one of a plurality of circuit fluidsources or utilization means. It is, therefore, an object of the presentinvention to provide a fluid handling switch adapted for fluid systemsof the kind utilizing fluidic logic components and adapted tointercommunicate a fluid source with at least one of a plurality offluid utilizing systems. In order topermit such fluid utilizing systemsto become emptied when not connected to the source of fluid pressure, itis a further object of the present invention to provide a fluid switchwhich is low in cost and is adapted to intercommunicate a source offluid with at least one of a plurality fluid utilizingsystems which alsoincludes means for automatically venting the unused fluid utilizingsystems.

Keeping in mind the above objective to provide a switch which is simplein construction and low in cost, while providing means for venting fluidutilization circuits not currently in use, it is a still further objectof the present invention to provide a fluid switch having asubstantially arcuate shaped rocker member having a flat surfaceperpendicular to the axis of rotation which cooperates with a perforatedflat surface on the switch body to perform the switching function withthe flat surfaces further cooperating to provide sealing for theintercommunication sufficient to prevent leakage of fluid in excess ofthe maximum permissible in a fluid logic system.

SUMMARY OF THE INVENTION The present invention comprises a rocker switchportion pivotally mounted in a housing with the pivotal member having aflat surface resiliently biased toward a cooperating surfaceof thehousing such that switching is achieved by a channel in the rockermember flat surface and the cooperating surfaces, assisted by theresiliently biasing detent mechanism, provide a fluid seal. The rockerswitch portion is further perforated to provide the necessary venting ofthe unused fluid utilizing systems.

BRIEF DESCRIPTION OF THE DRAWING DETAILED DESCRIPTION OF THE PREFERREDEMBODIMENT Referring now to FIGS. 1 and 2, a switch 10, according to thepresent invention, is shown with aportion of the switch body 12 brokenaway in FIG. 1 to illustrate the'resiliently biasing detent means 14.The detent means 14 comprise a resilient member 16 having a projectingtab or finger 18 from which protrudes convexity 20 which is operative toengage concavi- -ties 22 and 24 on the side of rocker switch member 26.The

rocker member 26 is pivotably mounted on pin 28 which, as is best shownin FIG. 2, is mounted in the switch body 12. Since the rocker member 26is shown as being comprised of the major segment of a right circularcylinder, it should be readily apparent that the member 26 could berestrained for pivotal movement about an axis by replacing pins 28 withrestraining guide means located at strategic points around the peripheryof the member 26.

The resiliently biasing detent mechanism 14 is connected to the switchbody 12 by conventional means, shown here as threaded bolts 30 and 32.Fluid coupling members 34, 36 and 38 are shown extending from the lowerportion of body 12 and which, as best shown in FIGS. 2' and 3,communicate with fluid passages extending into the body 12 to ultimatelycommunicate with the flat switching surface 27 of rocker member 26.Cover plate 13 is connected to body 12 to provide a complete switchmodule.

Referring now to FIG. 2 wherein a sectional view of the switch of FIG. Iis shown, the relationship between the switch body 12, detent means 14and rocker member 26 is. more clearly illustrated. In the switchposition illustrated, convexity 20 is shown as received by concavity 24so as to maintain the switch in a stable position. The resilient finger18 is operative to maintain the switch position and is also furtheroperative to bias the rocker member 26 towards the switch body- 12.

Referring now to FIGS. 3 and 4, particular emphasis is placed on therelation between the fluid passages in the switch body 12 and thechannel and passages in the pivotal member 26. Each fluid coupling 34,36 and 38 communicates directly with a fluid conduit or passage 40, 42,44 which, with reference to FIG. 2, rises upwardly into the body of theswitch and then turns toward the pivotal member26 where each terminatesin an orifice. Each orifice is positioned an equal distance from thepivoting axis, located in this preferred embodiment at the pin 28.

Referring now specifically to FIG. 4, the pivotal member 26 is shown inan elevational view. The pivotal member 26 includes two passages 52 and54 which pass through the pivotal member 26 and lie on either side of achannel 56 positioned at the center of the arc circumscribed by thearcuate section of the switch. The passages 52 and 54 and the channel 56are substantially equidistant from the pivotal axis and are arranged tocoincide with the orifices 46, 48 and 50 of the passages 40, 42 and 44so that the channel will intercommunicate the center orifice 48 witheither of the outer orifices while one of the passages 52 and 54 willcommunicate the other orifice to the ambient pressure existing on theother side of the switch.

In operation, the center fluid coupling 36 is connected to a source ofpressurized fluid so that the fluid is communicated to the passage 42and thence to the channel 56-. In one position the channel communicatesthe pressurized fluid to one of the outer passages 40 and 44, while theother of the passages is communicated, via either of passages 52 and 54,through pivotal member 26 to the opposite side thereof to serve as ameans for venting the nonused fluid circuit. Since surface 27 is flatand mates with a similarly flatsurface on switch body 12 and the pivotalmember is permanently biased toward the switch body 12 by resilientfinger 18, there exists a very low leakage virtual seal for fluidthrough the channel 56. The detent and biasing means 14 preventsinadvertent switching, but due to the small amount of penetration of theconcavities 22 and 24 by the convexity 20, intentional switching is notinhibited. By suitable choice of material for the pivotal member, thelarge contact surface will not inhibit the switching action.Furthermore, since all forces exerted on the pivotal member 26 aresubstantially parallel with the pivotal axis, any wear which would occurwill not alter the relationship between the various passages in the body12 and in the pivotal member 26. This has the advantage of maintainingfluid flow and adequate sealing over the life of the switch with theminimum moving parts, the pivotal member 26 and the resilient finger 18.

I claim:

l. A fluid switch comprising:

a switch body having a substantially flat surface and a plurality ofpassages passing through said body and having orifices in said flatsurface;

a switch member retained in said body and having a substantially flatsurface arranged in sliding contact with said switch body flat surfaceand a side opposite to said flat surface;

means for pivotally retaining said switch member in said switch bodyproviding said switch member with a pivotal axis perpendicular to saidflat surfaces;

said orifices arranged to be equidistant from said pivotal axis;

biasing means operative to bias saidflat surfaces into contactivesliding engagement; said switch member including a plurality of passagespassing therethrough, each of said passages having an orifice in theswitch member flat surface equidistant from said pivotal axis, and achannel formed in said flat surface, said channel being adapted tointercommunicate two of said body passage orifices; said flat surfacefurther operative to provide a fluid seal surrounding the orifices ofsaid plurality of passages and said channel; 1

said switch member passage orifices and said switch body passageorifices being substantially the same distance from said pivotal axis;means formed in said opposite side of the switch member operative toreceive pressure from said biasing means whereby switch position may bemaintained in any one of a plurality of positions; and

said switch member is comprised of a major arcuate segment of a rightcircular cylinder and said channel is positioned at the center of thearc circumscribed by said arcuate segment.

2. The switch as claimed in claim 1 wherein said plurality of switchbody passages is at least three in number.

3. The switch as claimed in claim 2 wherein said switch member passagesare adapted to communicate one of said at least three switch bodypassages through said switch member when said channel isintercommunicating two of the remaining at least three switch bodypassages.

1. A fluid switch comprising: a switch body having a substantially flatsurface and a plurality of passages passing through said body and havingorifices in said flat surface; a switch member retained in said body andhaving a substantially flat surface arranged in sliding contact withsaid switch body flat surface and a side opposite to said flat surface;means for pivotally retaining said switch member in said switch bodyproviding said switch member with a pivotal axis perpendicular to saidflat surfaces; said orifices arranged to be equidistant from saidpivotal axis; biasing means operative to bias said flat surfaces intocontactive sliding engagement; said switch member including a pluralityof passages passing therethrough, each of said passages having anorifice in the switch member flat surface equidistant from said pivotalaxis, and a channel formed in said flat surface, said channel beingadapted to intercommunicate two of said body passage orifices; said flatsurface further operative to provide a fluid seal surrounding theorifices of said plurality of passages and said channel; said switchmember passage orifices and said switch body passage orifices beingsubstantially the same distance from said pivotal axis; means formed insaid opposite side of the switch member operative to receive pressurefrom said biasing means whereby switch position may be maintained in anyone of a plurality of positions; and said switch member is comprised ofa major arcuate segment of a right circular cylinder and said channel ispositioned at the center of the arc circumscribed by said arcuatesegment.
 2. The switch as claimed in claim 1 wherein said plurality ofswitch body passages is at least three in number.
 3. The switch asclaimed in claim 2 wherein said switch member passages are adapted tocommunicate one of said at least three switch body passages through saidswitch member when said channel is intercommunicating two of theremaining at least three switch body passages.